bug#17744: 24.3.91; Cursor drawn at EOL while it's at BOL

[Stefan <monnier@iro.umontreal.ca>]

   emacs -Q

   (progn (goto-char (point-min)) (forward-line 1)
     (let ((ol (make-overlay (point) (point)))
           (str "TOTO"))
       (put-text-property 0 1 'cursor 1 str)
       (overlay-put ol 'after-string str)))

Then do:

   M-<
   C-n

Notice that the cursor is drawn at EOL whereas it should be drawn at BOL.

   C-f C-f

this confirms that point really is where we want it to be, it's only the
cursor drawing code which is playing tricks.

This bug is visible in rectangle-mark-mode when the cursor is at BOL
right in front of a TAB and the other side of the rectangle ends in the
middle of that TAB.




In GNU Emacs 24.3.91.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.23)
 of 2014-06-06 on pastel
Repository revision: monnier@iro.umontreal.ca-20140606142539-5h50ienhp3mpz68z
Windowing system distributor `The X.Org Foundation', version 11.0.11500901
System Description:	Debian GNU/Linux 7.5 (wheezy)

Configured using:
 `configure -C --enable-checking --enable-check-lisp-object-type
 'CFLAGS=-Wall -g3 -Og -Wno-pointer-sign''

Important settings:
  value of $LANG: fr_CH.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp

Minor modes in effect:
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-s p l a c e - c u r s o C-s C-s C-a <right> <right> 
<right> <down> <right> <left> C-x SPC <up> <up> <up> 
<right> <right> <right> <right> C-x C-x C-g M-: ( l 
e t SPC <M-backspace> s e t q SPC s m - t <backspace> 
o l SPC ( m a k e - o v e r l a y SPC ( p o i n t ) 
SPC ( p o i n t ) ) ) <return> M-: ( o v e r l a y 
- p u t <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> s e t q SPC s m t e <backspace> 
<backspace> - t e s t SPC " T O T O " ) <return> M-: 
( p u t - t e x t - p r o <M-tab> SPC 0 SPC 1 SPC ' 
c u r s o r SPC 1 SPC s m - t e s t ) <return> M-: 
s m - t e s t <return> M-: ( o v e r l a y - p u t 
SPC s m - o l SPC ' a f t e r - s t r i n g SPC s m 
- t e s t ) <return> <left> <right> <right> <right> 
<right> <right> <left> <left> <left> <left> <left> 
<right> <right> <right> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> M-x r e p o - e m - b <tab> 
<return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Mark saved where search started
Mark set
Mark set (rectangle mode)
Quit [2 times]
#<overlay from 22331 to 22331 in rect.el>
"TOTO"
nil
#("TOTO" 0 1 (cursor 1)) [2 times]

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util help-fns mail-prsvr mail-utils rect misearch multi-isearch
vc-bzr time-date tooltip electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt
fringe tabulated-list newcomment lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dbusbind
gfilenotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 8 73264 6135)
 (symbols 24 17632 0)
 (miscs 20 63 350)
 (strings 16 9931 4370)
 (string-bytes 1 271526)
 (vectors 8 9748)
 (vector-slots 4 383535 5334)
 (floats 8 67 327)
 (intervals 28 432 21)
 (buffers 512 12)
 (heap 1024 20818 707))